METHOD FOR SPARK DECONTAMINATION OF SURFACES WITH CLOSED-CIRCUIT WATER SUPPLY CYCLE Russian patent published in 2001 - IPC

FIELD: decontamination of metal surfaces contaminated by radionuclides. SUBSTANCE: part having contaminated metal surface is placed in working vessel wherein movable electrode is placed so that it is spaced apart from surface to be decontaminated through gap of 0.05 to 1 mm. Part and electrode are connected to pulse generator leads, demineralized water is injected in mentioned gap at speed of at least 0.1 m/s, and spark discharge is started. High temperature of spark discharge causes fusion of metal surface layer. Fused metal is ejected from crater at moment of discharge quenching under action of electrohydraulic shock and is dispersed into small droplets which are cooled down in cold water and granulated. Granules and all products of pyrolysis are evacuated from gap under action of water jet pressure. Water is cleaned of granules as well as of dissolved radioactive particles and metal salts and returned to decontamination zone. In this way demineralized water circulates in closed loop and desired proportion of solid and liquid radioactive wastes is maintained. EFFECT: provision for multiple reuse of demineralized water and for stabilizing proportion of solid and liquid wastes. 10 cl, 3 ex